Thermal compression method for increasing 40Cr / Q345B interface bonding width

Abstract

The invention discloses a hot compression method for increasing the bonding width of a 40Cr / Q345B interface, and belongs to the technical field of bimetal component manufacturing. The method is characterized by comprising the following steps that (1) before hot compression, a bimetal blank is taken into a bimetal ring blank formed through a centrifugal casting process, 40Cr steel is arranged on the upper side in the height direction of the bimetal blank, Q345B steel is arranged on the lower side in the height direction of the bimetal blank, the diameter of the bimetal blank is D0, the height of the bimetal blank is H0, and the interface bonding width of the bimetal blank is B0; and (2) after hot compression, the height of the bimetal blank is reduced to H, the diameter is increased to D, the interface bonding width is increased to B, a mathematical model of the bonding width B, the compression temperature T and the rolling reduction epsilon is designed, and the interface bonding width B can be determined according to the temperature and the rolling reduction. The method has the advantages that the combination width can be simply and conveniently determined through the mathematical model according to the given compression temperature and rolling reduction, the design efficiency is improved, and the bimetallic composite material with good interface combination is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of bimetallic component manufacturing, and in particular relates to a hot compression method for improving the bonding width of a 40Cr / Q345B bimetallic interface. Background Art

[0002] With the rapid development of the manufacturing and application needs of high-end equipment and its components (such as flanges and slewing support rings) in the fields of aerospace, deep-sea exploration and rail transportation, the requirements for the comprehensive performance of metal components are becoming more and more stringent. Components made of a single material are increasingly difficult to meet the service requirements under extremely complex working conditions. After the surface of a traditional single material is worn to a certain extent, it will cause a lot of waste due to unusability, which has led to the manufacture and application of bimetallic composite components. The unused part is replaced by other cheap materials, especially in applications where the performance requirements for the inner and outer sides of the components are inconsistent, which can achieve the purpose of saving costs and improving performance.

[0003] The bonding performance of bimetallic composites mainly depends on the bonding width of the bimetallic interface. However, in the current research on bimetallic composites, there is no unified design standard for the interface bonding width, and there is no clear standard for its relationship with the corresponding composite process parameters, which seriously affects the improvement of the bonding performance of bimetallic composites. Summary of the invention

[0004] The present invention provides a method for hot compressing the bonding width of a 40Cr / Q345B bimetallic interface, which can effectively overcome the shortcomings of the prior art.

[0005] The object of the present invention is achieved by comprising the following steps:

[0006] 1. A hot compression method for increasing the interface bonding width of 40Cr / Q345B, belonging to the technical field of bimetallic component manufacturing, is characterized by being implemented in the following steps:

[0007] (1) Before hot compression, the bimetallic billet is cylindrical. The bimetallic ring billet formed by the centrifugal casting process is taken. Along the height direction of the bimetallic billet, the upper side is 40Cr steel and the lower side is Q345B steel. The geometric dimensions of the bimetallic billet are set as follows: diameter D 0 , height H 0 , where the interface bonding width after centrifugal casting is B 0 ;

[0008] (2) After hot compression, the height of the bimetallic blank is set to be reduced to H, the diameter is increased to D, and the interface bonding width is increased to B. A mathematical model of the bonding width B, temperature T, and reduction ε is designed, namely:

[0009] B = 1 2 [ 1 . 41987 × exp ( T 768 . 55952 ) + 3 . 09952 × exp ( ε 0 . 76856 ) − 7 . 15596 ] (1)

[0010] As described in step (2), the temperature T = 900~1200 °C, the reduction ε = 30~60%, and the interface bonding width B can be determined based on the temperature and the reduction.

[0011] As described in step (2), the interface bonding width can also be found from the following table:

[0012] Relationship table between interface bonding width B and thermal compression process parameters

[0013]

[0014] The advantages and beneficial effects of the present invention are as follows: since the present invention takes into account the differences in deformation temperature and reduction during the hot compression process, and determines the relationship between the interface bonding width B, the deformation temperature T and the reduction ε, for a hot-compressed 40Cr / Q345B bimetallic billet of a certain size, the bonding width can be simply and quickly obtained by increasing the deformation temperature and the reduction, thereby improving the efficiency of dimensional design and shortening the process time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is the geometric dimension identification diagram of the bimetallic blank before and after hot compression;

[0016] In the figure: 1—40Cr steel 2—Q345B steel;

[0017] D 0 —Diameter of bimetal billet before hot compression, H 0 —Height of bimetal blank, B 0 —Bimetallic blank interface bonding width;

[0018] D—diameter of the bimetallic billet after hot compression, H—height of the bimetallic billet after hot compression, B—interface bonding width of the bimetallic billet after hot compression. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Figure 1 Geometric dimension diagram of bimetallic billet before and after hot compression.

[0021] Example 1

[0022] The process parameters of bimetal hot compression in this embodiment are as follows: a bimetal ring blank formed by centrifugal casting is taken, and along the height direction of the cylindrical bimetal blank, the upper side is 40Cr steel and the lower side is Q345B steel. The hot compression method of increasing the 40Cr / Q345B interface bonding width B is mainly achieved by increasing the deformation temperature T and the reduction ε. The design steps are:

[0023] (1) Before hot compression, the bimetal billet is cylindrical. A bimetal ring billet formed by centrifugal casting is taken. Along the height direction of the cylindrical bimetal billet, the upper side is 40Cr steel and the lower side is Q345B steel. The geometric dimensions of the bimetal billet are set as follows: diameter 18 mm, height 27 mm, and the interface metallurgical bonding width after centrifugal casting is 0.5 mm.

[0024] (2) After hot compression, the height of the bimetallic blank is set to be reduced to 18.9 mm and the diameter is increased to 21.52 mm. When the temperature is 900 °C and the reduction is 30%, the bonding width B can be determined:

[0025] B = 1 2 [ 1 . 41987 × exp ( 900 768 . 55952 ) + 3 . 09952 × exp ( 0 . 3 0 . 76856 ) − 7 . 15596 ] = 1 . 00 mm

[0026] Example 2

[0027] The process parameters of bimetal hot compression in this embodiment are as follows: take a bimetal ring blank formed by centrifugal casting process, along the height direction of the cylindrical bimetal blank, the upper side is 40Cr steel and the lower side is Q345B steel. The hot compression method of increasing the 40Cr / Q345B interface bonding width B is mainly achieved by increasing the temperature T and the reduction ε. The design steps are:

[0028] (1) Before hot compression, the bimetal billet is cylindrical. A bimetal ring billet formed by centrifugal casting is taken. Along the height direction of the cylindrical bimetal billet, the upper side is 40Cr steel and the lower side is Q345B steel. The geometric dimensions of the bimetal billet are set as follows: diameter 18 mm, height 27 mm, and the interface metallurgical bonding width after centrifugal casting is 0.5 mm.

[0029] (2) After hot compression, the height of the bimetallic blank is set to be reduced to 14.85 mm and the diameter is increased to 24.27 mm. When the temperature is 1050 °C and the reduction is 45%, the bonding width B can be determined:

[0030] B = 1 2 [ 1 . 41987 × exp ( 1050 768 . 55952 ) + 3 . 09952 × exp ( 0 . 45 0 . 76856 ) − 7 . 15596 ] = 1 . 99 mm

[0031] Example 3

[0032] The process parameters of bimetal hot compression in this embodiment are as follows: take a bimetal ring blank formed by centrifugal casting process, along the height direction of the cylindrical bimetal blank, the upper side is 40Cr steel and the lower side is Q345B steel. The hot compression method of increasing the 40Cr / Q345B interface bonding width B is mainly achieved by increasing the temperature T and the reduction ε. The design steps are:

[0033] (1) Before hot compression, the bimetal billet is cylindrical. A bimetal ring billet formed by centrifugal casting is taken. Along the height direction of the cylindrical bimetal billet, the upper side is 40Cr steel and the lower side is Q345B steel. The geometric dimensions of the bimetal billet are set as follows: diameter 18 mm, height 27 mm, and the interface metallurgical bonding width after centrifugal casting is 0.5 mm.

[0034] (2) After hot compression, the height of the bimetallic blank is reduced to 10.8 mm and the diameter is increased to 28.46 mm. When the temperature is 1200 °C and the reduction is 60%, the bonding width B can be determined:

[0035] B = 1 2 [ 1 . 41987 × exp ( 1200 768 . 55952 ) + 3 . 09952 × exp ( 0 . 6 0 . 76856 ) − 7 . 15596 ] = 3 . 19 mm .

Claims

1. A hot compression method for increasing the interface bonding width of 40Cr / Q345B, belonging to the technical field of bimetallic component manufacturing, characterized in that Follow these steps to achieve this: (1) Before hot compression, the bimetal billet is cylindrical. A bimetal ring billet formed by a centrifugal casting process is obtained. Along the height direction of the bimetal billet, the upper side is 40Cr steel and the lower side is Q345B steel. The geometric dimensions of the bimetal billet are set as follows: diameter D0, height H0, where the interface bonding width after centrifugal casting is B0; (2) After hot compression, the height of the bimetallic blank is set to be reduced to H, the diameter is increased to D, and the interface bonding width is increased to B. A mathematical model of the bonding width B, temperature T, and reduction ε is designed, namely: （1）。 2. A hot compression method for increasing the 40Cr / Q345B interface bonding width according to claim 1, characterized in that: The temperature T=900~1200 ℃, the reduction ε=30~60%, and the interface bonding width B can be determined based on the temperature and reduction.

3. A hot compression method for increasing the 40Cr / Q345B interface bonding width according to claim 1, characterized in that: The interface bonding width can also be found from the following table: Relationship table between interface bonding width B and thermal compression process parameters 。

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